A device, possibly a hand grenade, was thrown toward the stage on which President Bush addressed 300,000 cheering Georgians on Tuesday, but it was not discovered until after the president’s appearance, NBC News has learned.

Local police told the Secret Service the device was thrown as Bush spoke in Freedom Square in Tblisi, the Georgian capital. The device hit someone and fell to the ground about 100 feet away from the stage, the Secret Service said.

The Secret Service said it was unaware of any disturbance until it was informed of the incident by Georgian police.